La"cing (?), n. 1. The act of securing, fastening, or tightening, with a lace or laces.

2. A lace; specifically (Mach.), a thong of thin leather for uniting the ends of belts.

3. A rope or line passing through eyelet holes in the edge of a sail or an awning to attach it to a yard, gaff, etc.

4. (Bridge Building) A system of bracing bars, not crossing each other in the middle, connecting the channel bars of a compound strut. Waddell.